Mepazine, i.e., the compound 10-[(1-methylpiperidin-3-yl)methyl]-10H-phenothiazine, was initially used as a tranquilizer (Lord and Archibald, Can. J. Comp. Med. Vet. Sci., 1957, 21, 391-394). The structurally very similar compounds 10-[2-(1-methylpiperidin-2-yl)ethyl]-2-(methylthio)phenothiazine (thioridazine) and N,N-dimethyl-1-(10H-phenothiazin-10-yl)propan-2-amine (promethazine) are known in the art as antipsychotic drugs and exert sedative effects by acting as dopamine receptor antagonists (Seeman and Lee, Science, 1975, 188, 1217-1219). Recently, it has been found that certain phenothiazine derivatives are inhibitors of a paracaspase, in particular inhibitors of MALT1, and, thus, are useful in treating disorders and diseases in the development of which dysregulation of the activity of the paracaspase (in particular MALT1) plays a crucial role. Exemplary disorders/diseases which are treatable by the phenothiazine derivatives include diffuse-large B cell lymphoma (DLBCL) and multiple sclerosis.
In view of the above, it would be desirable to provide compounds exhibiting an improved therapeutic profile (e.g., improved pharmacological and/or metabolic properties, such as higher activity against a paracaspase and reduced sedative and/or antipsychotic effect). A further object of the present application is the provision of a process for the preparation of such compounds.